Speaker: Shiuan-Li Lin Advisor : Sheng-Lung Huang E-beam Lithography Speaker: Shiuan-Li Lin Advisor : Sheng-Lung Huang Solid-State Laser Crystal and Device Laboratory

Outline E-beam lithography Operation & application Conclusion 1. E-beam components 2. Scanning methods 3. Exposure 4. Some type of photoresists 5. Advantages & disadvantages Operation & application Conclusion Solid-State Laser Crystal and Device Laboratory Page 2

E-beam components: An electron gun or electron source that supplies the electrons. An electron column that 'shapes' and focuses the electron beam. A mechanical stage that positions the wafer under the electron beam. A wafer handling system that automatically feeds wafers to the system and unloads them after processing. A computer system that controls the equipment.

Scanning methods: Raster Scan: The e-beam is swept across the entire surface, pixel by pixel, with the beam being turned on and off according to the desired pattern. Vector Scan: The e-beam “jumps” from one patterned area to the next, skipping unwanted areas. This makes the vector scan much faster. Solid-State Laser Crystal and Device Laboratory Page 4

Optical EBL Exposure: 1.Mask required 2.Parallel 3.Limited by wavelength of light, diffraction and resist properties 1.Serial, point by point 2.Not limited by wavelength of electrons 3.Limited by resist properties EBL exposure is governed with the formula: beam current ✕ exposure time Total charge of incident electrons = step size =dose ✕ exposed area Solid-State Laser Crystal and Device Laboratory Page 5

Some type of photoresists: PMMA (polymethyl methacrylate) ultra-high resolution, high contrast positive resist.It has poor sensitivity and poor dry etch resistance,but it sticks well to almost any surface ZEP520A positive resists which show high resolution (rectangle pattern profile) and dry etch resistance, suitable for various EB processes ESPACER 1.spin coatable, no evaporation required & water soluble 2.Ebeam exposure must occur shortly after Espacer application Solid-State Laser Crystal and Device Laboratory Page 6

Scanning methods: Advantages: 1. Smaller line width than with UVL. 2. Flexible 3. Industrial application: mask making for UV lithography. Disadvantages: 1. Electron Backscattering : when electrons are subjected directly to a surface, they tend to “scatter” quickly, causing unwanted reactions to take place outside of the focused electron beam 2. slow exposure times & high price Solid-State Laser Crystal and Device Laboratory Page 7

Operation & application Here comes your footer  Page 8

Lithography steps: 2. e-beam patterning 3. Development 1. Resist Coating Development 2-layer resist: ESPACER ZEP520A Substrate(SiO2) 4.4.2010

Operation & Application ELS-7000(ELIONIX) SEM observation unit Electron gun emitter ZrO／W Thermal Field Emission Acceleration voltage 25, 50, 75, 100kV Minimum line width 8~10 nm Lithography method direct writing with vector scanning Electron beam current 1×10－12 ～ 2×10－9A Scanning field 2,400μm×2,400μm 1,200μm×1,200μm、600μm×600μm….etc Picture element MAP 240,000×240,000dot 60,000×60,000dot 20,000×20,000dot Solid-State Laser Crystal and Device Laboratory Page 10

Operation & Application 烘烤機 旋轉塗佈機 於基板上塗佈ESPACER Solid-State Laser Crystal and Device Laboratory Page 11

Operation & Application 基板放置(需要準確放置於兩金板之間) 推送sample進腔體前,需等待小腔體之真空度達一定的標準後才可推送 Solid-State Laser Crystal and Device Laboratory Page 12

Operation & Application PICOAMMETER Faraday cup Solid-State Laser Crystal and Device Laboratory Page 13

Operation & Application 可繪製:直線,方框,圓形,三角…. 也可讀取autoCAD圖檔! 3.67μm Solid-State Laser Crystal and Device Laboratory Page 14

Conclution E-beam lithography is particularly important in micro electronics, which require extremely precise placement of micro sized circuit elements Electrons can be used to etch a “mask” whose patterns can be later transferred onto a substance using other techniques 乖乖? Solid-State Laser Crystal and Device Laboratory Page 15

Thanks for your listening! bee6565 Solid-State Laser Crystal and Device Laboratory Page 16